Shirley Conran's Lace is to be republished this summer, 30 years after it became the ultimate escapist fiction, for a generation of women. Just whisper the word "goldfish" to any woman in her late 30s or early 40s and see how many of them blush.

These days, if Lace is remembered at all it is as the ultimate bonkbuster, a brick of a book, stuffed full of graphic sex scenes and the memorable line: "Which one of you bitches is my mother?" It has recently been dismiissed as little more than the precursor to the sex and shopping saga and surprisingly, to this reader at least, as "erotica".

Yet, while Lace might seem to be another extravagantly plotted tale of sex and revenge, like Lisa Alther's Kinflicks or Rona Jaffe's Class Reunion, it is more than just a racy tale. This is not one of chick-lit's Cinderella stories with a sunny girl-meets-boy plot, but darker, more complicated fare.

Conran's heroines may get their happily-ever-after but it's usually despite and not because of a man. Her novel is that rare thing: a feminist tract disguised as a bonkbuster.

Don't believe me? Consider this: the focus of the book is not so much Lily's hunt for her mother as it is the friendship between our four heroines – Judy, Maxine, Kate and Pagan – all of whom are shown struggling to find some form of autonomy during the 60s and 70s.

There are disastrous marriages and illicit affairs, but Conran, who memorably wrote in Superwoman that life was "too short to stuff a mushroom", is most interested in her heroines' careers.

We watch Judy rise to the top in fashion, then magazine publishing, Kate becomes a war correspondent and Maxine makes her name in interior design. Pagan struggles with being a society wife in Cairo and her aristocratic world crumbles as the times inexorably change.

Along the way Conran tackles everything from teenage abortion and the iniquities of the porn industry to double standards around one-night stands. We remember the vividly described sex scenes, but in reality the book is filled with pages of argument about a woman's right to work, the need for equal pay and the juggling of children and career.

Notably, those children – the mysterious Lily apart – largely play a background role while the men, with the notable exception of the creepily exoticised Prince Abdullah, are dutiful consorts, turning up to escort the women to glamorous events or to drive the plot by explaining recessive genes.

Most of all, in contrast to its modern-day equivalent, the bland Fifty Shades of Grey and its sado-masochism by numbers, Lace is exuberantly, fabulously over-the-top. Its heroines suffer no fools, take no prisoners and leave few bonkbuster cliches unused. Ultimately, after almost 700 pages of sex, sin and scandal the book ends by demonstrating that female friendship – sticking together through "Sick and Sin" as Maxine describes it – is more important than any man.